1. Field of Invention
The present invention relates to a backlight photographing method, and more particularly to a photographing method in which photographing parameters of a digital camera are adjusted after backlight detection.
2. Related Art
A backlight photographing situation might occur both indoors and outdoors for photographing with a digital camera. The backlight photographing usually make foreground (that is, predetermined object to be photographed) too dark and background too bright, such that the foreground is unable to be clearly seen in the obtained photo.
In order to overcome this backlight photographing problem, persons in the industry propose different solutions. For example, in Taiwan Patent Application No. 200821742 published on May 16, 2008, a system and a method for flashlight control for backlight photographing are disclosed. In this solution, a difference of aperture values between background and foreground is set first and flashlight is then utilized for compensation. A subject to be photographed is first metered to obtain an aperture value of the foreground. Then the background is metered, and an aperture value of the background is obtained similarly. The difference of aperture values between the background and the foreground is then set. Subsequently, the subject is focused, so as to calculate a distance of the subject. Next, a required flashlight index of the flashlight is calculated according to the aperture value obtained from the aperture value difference for backlight photographing.
In Taiwan Patent No. 501364, issued on Sep. 1, 2002, a camera device and a photographing method are proposed. The method and device utilize software for backlight determination.
In U.S. Pat. No. 6,950,141, a camera that controls image sensor exposure is disclosed. In a front-lighted, back-lighted or over-front-lighted condition, an average exposure is obtained. Especially, the area to be photographed is divided into 64 regions. The camera compares the regions to calculate an average brightness, including an average value of an upper half of the image, an average value of a lower half of the image, and average values for other different considerations, thereby controlling the exposure of an image sensor accordingly.
As can be seen from the solutions proposed in the industry, it is a goal requiring constant efforts for the industry to photograph a photo with a good image effect in backlight.